Commit 7a387bed authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov

scripts/bpf: teach bpf_helpers_doc.py to dump BPF helper definitions

Enhance scripts/bpf_helpers_doc.py to emit C header with BPF helper
definitions (to be included from libbpf's bpf_helpers.h).
Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 5f0e5412
......@@ -391,6 +391,154 @@ SEE ALSO
print('')
class PrinterHelpers(Printer):
"""
A printer for dumping collected information about helpers as C header to
be included from BPF program.
@helpers: array of Helper objects to print to standard output
"""
type_fwds = [
'struct bpf_fib_lookup',
'struct bpf_perf_event_data',
'struct bpf_perf_event_value',
'struct bpf_sock',
'struct bpf_sock_addr',
'struct bpf_sock_ops',
'struct bpf_sock_tuple',
'struct bpf_spin_lock',
'struct bpf_sysctl',
'struct bpf_tcp_sock',
'struct bpf_tunnel_key',
'struct bpf_xfrm_state',
'struct pt_regs',
'struct sk_reuseport_md',
'struct sockaddr',
'struct tcphdr',
'struct __sk_buff',
'struct sk_msg_md',
'struct xpd_md',
]
known_types = {
'...',
'void',
'const void',
'char',
'const char',
'int',
'long',
'unsigned long',
'__be16',
'__be32',
'__wsum',
'struct bpf_fib_lookup',
'struct bpf_perf_event_data',
'struct bpf_perf_event_value',
'struct bpf_sock',
'struct bpf_sock_addr',
'struct bpf_sock_ops',
'struct bpf_sock_tuple',
'struct bpf_spin_lock',
'struct bpf_sysctl',
'struct bpf_tcp_sock',
'struct bpf_tunnel_key',
'struct bpf_xfrm_state',
'struct pt_regs',
'struct sk_reuseport_md',
'struct sockaddr',
'struct tcphdr',
}
mapped_types = {
'u8': '__u8',
'u16': '__u16',
'u32': '__u32',
'u64': '__u64',
's8': '__s8',
's16': '__s16',
's32': '__s32',
's64': '__s64',
'size_t': 'unsigned long',
'struct bpf_map': 'void',
'struct sk_buff': 'struct __sk_buff',
'const struct sk_buff': 'const struct __sk_buff',
'struct sk_msg_buff': 'struct sk_msg_md',
'struct xdp_buff': 'struct xdp_md',
}
def print_header(self):
header = '''\
/* This is auto-generated file. See bpf_helpers_doc.py for details. */
/* Forward declarations of BPF structs */'''
print(header)
for fwd in self.type_fwds:
print('%s;' % fwd)
print('')
def print_footer(self):
footer = ''
print(footer)
def map_type(self, t):
if t in self.known_types:
return t
if t in self.mapped_types:
return self.mapped_types[t]
print("")
print("Unrecognized type '%s', please add it to known types!" % t)
sys.exit(1)
seen_helpers = set()
def print_one(self, helper):
proto = helper.proto_break_down()
if proto['name'] in self.seen_helpers:
return
self.seen_helpers.add(proto['name'])
print('/*')
print(" * %s" % proto['name'])
print(" *")
if (helper.desc):
# Do not strip all newline characters: formatted code at the end of
# a section must be followed by a blank line.
for line in re.sub('\n$', '', helper.desc, count=1).split('\n'):
print(' *{}{}'.format(' \t' if line else '', line))
if (helper.ret):
print(' *')
print(' * Returns')
for line in helper.ret.rstrip().split('\n'):
print(' *{}{}'.format(' \t' if line else '', line))
print(' */')
print('static %s %s(*%s)(' % (self.map_type(proto['ret_type']),
proto['ret_star'], proto['name']), end='')
comma = ''
for i, a in enumerate(proto['args']):
t = a['type']
n = a['name']
if proto['name'] == 'bpf_get_socket_cookie' and i == 0:
t = 'void'
n = 'ctx'
one_arg = '{}{}'.format(comma, self.map_type(t))
if n:
if a['star']:
one_arg += ' {}'.format(a['star'])
else:
one_arg += ' '
one_arg += '{}'.format(n)
comma = ', '
print(one_arg, end='')
print(') = (void *) %d;' % len(self.seen_helpers))
print('')
###############################################################################
# If script is launched from scripts/ from kernel tree and can access
......@@ -405,6 +553,8 @@ Parse eBPF header file and generate documentation for eBPF helper functions.
The RST-formatted output produced can be turned into a manual page with the
rst2man utility.
""")
argParser.add_argument('--header', action='store_true',
help='generate C header file')
if (os.path.isfile(bpfh)):
argParser.add_argument('--filename', help='path to include/uapi/linux/bpf.h',
default=bpfh)
......@@ -417,5 +567,8 @@ headerParser = HeaderParser(args.filename)
headerParser.run()
# Print formatted output to standard output.
printer = PrinterRST(headerParser.helpers)
if args.header:
printer = PrinterHelpers(headerParser.helpers)
else:
printer = PrinterRST(headerParser.helpers)
printer.print_all()
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